Nokia 808 PureView Review

DxOMark Mobile Report: Nokia Pureview 808

Summary

Note: all the observations are based on results obtained using the Pureview 8MPixel mode. DXOMark's engineers were highly impressed with the Nokia 808 Pureview, noting that "this smartphone camera is the best tested by our Lab so far with a Photo Mobile Score of 81." They noted that the 808 offers "very good detail preservation even in low light conditions," and boasts "excellent noise management in low light conditions, far ahead of its direct competitors at its release." On the downside they criticized the less than perfect autofocus when shooting at close range and occasional exposure errors when shooting under difficult lighting conditions (such as scenes with a high dynamic range or with backlit subjects). Video also produced "very good performance in bright light, with pleasant colors," but DxOMark reported "very noisy" results in low light and that the stabilization system was far from 100% reliable.

Still Photography

Color, Exposure and Contrast

The DxOMark team found the Pureview 808 to produce "pleasant colors in every conditions, less saturated than on most smartphones", with "hardly noticeable" color shading, but that they experienced occasional "Small exposure failures (over or under exposure in some difficult outdoor pictures." Overall DxOMark scored the Purview 78/100 for Exposure and Contrast, an excellent 82/100 for Color (in bright light) and 77/100 for Color in low light.

Drilling down a little into the detail, DxOMark awarded the Pureview 808, based on both measured and perceptual analysis, scores of:

4.1 out of 5 for Exposure,

4.0 out of 5 for White Balance accuracy

4.0 out of 5 for Color shading in low light*

4.5 out of 5 for Color shading in bright light*

3.5 out of 5 for Color Rendering in low light, and

4.0 out of 5 for Color Rendering in bright light

DxOMark noted that in low light conditions (20 Lux, tungsten - equivalent to a very dimly lit interior) the 808 did produce a slight yellow cast, but that "Despite the color cast, colors are vivid and pleasant."

Outdoors, with good lighting condition they described colors as "pleasant, but the contrast is not maximized."

*Color Shading is the nasty habit cellphone cameras have of rendering different areas of the frame with different color shifts, resulting in pictures with, for example, pinkish centers and greenish corners. The Pureview 808 didn't exhibit significant shading in bright light, and only a little in the very lowest light conditions (20 Lux).

Noise and Details

DxOMark's engineers reported that the Pureview 808 captures images that show "Impressive detail preservation even in low light conditions with 100% crops", and that "Noise level is very well controlled even in low light conditions." Unusually they found almost nothing to complain about.

Texture Acutance

Texture Acutance is a way of measuring the ability of a camera to capture images that preserve fine details, particularly the kind of low contrast detail (textures such as fine foliage, hair, fur) that can be blurred away by noise reduction or obliterated by excessive sharpening.

Sharpness is an important part of the quality of an image, but while it is easy to look at an image and decide visually whether it's sharp or not, the objective measurement of sharpness is less straightforward.

An image can be defined as 'sharp' if its edges are sharp and if fine details are visible, but in-camera processing means it's possible to have one of these (sharp edges) but not the other (fine details). Conventional MTF measurements tell us how sharp an edge is, but have drawbacks when it comes to measuring fine detail preservation. Image processing algorithms can detect edges and enhance their sharpness, but they can also find homogeneous areas and smooth them out, to reduce noise.

Texture Acutance, on the other hand, can qualify sharpness in terms of preservation of fine details, without being fooled by edge enhancement algorithms.

A detail of target made of a 'dead leaves' pattern, designed to measure Texture Acutance. It is obtained by drawing random shapes that occlude each other in the plane, like dead leaves falling from a tree. The statistics of this model follow the distribution of the same statistics in natural images.

In this example from a DSLR without edge enhancement sharpness seems equal on edge and on texture. Many details are visible in the texture.

In this second example edges have been digitally enhanced, and the edge looks over-sharp, with visible processing halos ('ringing'). On the texture part, many details have disappeared.

At first sight, the images from these two cameras may appear equally sharp. A sharpness measurement on edges will indeed confirm this impression, and will even show that the second camera is sharper. But a closer examination of low contrasted textures shows that the first camera has a better preservation of fine details than the second. The purpose of the Texture Acutance measurement is to qualify this difference.

Note:Acutance is a single value metric calculated from a MTF result. Acutance is used toassess the sharpness of an image as viewed by the human visual system, and is dependent on the viewing conditions (size of image, size of screen or print, viewing distance). Only the values of texture acutance are given here. The measurements are expressed as a percentage of the theoretical maximum for the chosen viewing condition. The higher the score, the more details can be seen in an image.

For all DxOMark Mobiledata presented on connect.dpreview.com we're showing only the '8MP equivalent' values, which gives us a level playing field for comparison between phone cameras with different megapixel values by normalizing all to 8MP, suitable for fairly large prints. DxOMark also offer this data for lower resolution use-cases (web and on-screen). For more information on DxOMark's testing methodology and Acutance measurements please visit the website at www.dxomark.com.

The Pureview 808 shows class-leading ability to retain fine texture even at 20 Lux (3.0 EV: very low light, such as a floodlit building at night); even better at 700 Lux (outdoors on an overcast day).

The Pureview 808 (green line) is the clear winner here, most noticeably in low light where its noise reduction algorithms do considerably less harm than any of the competitor models.

In these 100% crops you can clearly see what a remarkable job the 808 does at preserving texture even in very low light.

Edge Acutance

Edge acutance is a measure of the sharpness of the edges in images captured by the phone's camera, and again we're only looking at the most demanding of the three viewing conditions that DxOMark reports on, '8MP equivalent'.

The 808 uses very subtle sharpening compared to some competitors, but still offers very competitive edge acutance.

Visual Noise

Visual Noise is a value designed to assess the noise in an image as perceived by the human visual system, depending on the viewing condition (size of image, size of screen or print, viewing distance). The measurements have no units and can be simply viewed as a weighted average of noise standard deviation for each channel in the CIE L*a*b* color space. The lower the measurement, the less noise in the image.

Visual noise is remarkably low thanks to the innovative Pureview technology. This graph shows the results for daylight; those for tungsten light are almost identical.

Although there's not a lot of difference in bright light, in low light the Nokia 808 is the clear winner here, thanks to its groundbreaking 'PureView' technology.

Noise & Detail Perceptual scoring

DxOMark engineers don't just point camera phones at charts, they also take and analyse scores of real-world shots and score them accordingly. Their findings for the Nokia 808 PureView were:

Artifacts

Phone cameras, like entry-level compact cameras, tend to suffer from artifacts such as sharpening halos, color fringing, vignetting (shading) and distortion, which can impact on the visual appeal of the end result. DxOMark engineers measure and analyze a range of artifacts. Their findings after testing the Pureview 808 are shown below:

Pros:

Ringing level (halos) is negligible, extremely low compared to other camera phones, while sharpness and details are still excellent

Cons

Slight loss of sharpness in the corners

Very slight color fringes (red and blue) due to lateral chromatic aberration, only visible at 100% viewing.

Perceptual scores

Sharpness 4.0 out of 5

Color fringing 4.2 out of 5

Measured findings

Ringing center: 1.2%

Ringing corner 0.4%

Max geometric distortion 0.46%

Luminance shading 20%

Distortion & Chromatic Aberrations

the graph shows the magnification from center to edge (with the center normalized to 1). The Pureview 808 shows slight pincushion distortion, with a maximum geometric distortion of 0.46%. You are not going to notice this in normal photography.

Very slight color fringes (red and blue) are noticeable in real world shots (lateral chromatic aberrations)

Autofocus

DxOMark also tests autofocus accuracy and reliability by measuring how much the accutance - sharpness - varies with each shot over a series of 30 exposures (defocusing then using the autofocus for each one). As with other tests these results are dependant on the viewing conditions (a little bit out of focus matters a lot less with a small web image than a full 8MP shot viewed at 100%). In bright light the Pureview 808 did a great job, offering good autofocus accuracy and repeatability and earning a respectable 81/100 score. In low light things were far less impressive, especially in macro mode, when DxOMark found autofocus reliablity to be poor enough to drop the score to 66/100.

Flash

DxOMark scored the Nokia 808 a high 81/100 overall for its flash performance, noting it offers "Very good flash quality: good repeatability and good exposure" and very reliable white balance. The only demerit is the fall-off (darkening of corners).

Pros:

good flash quality: good repeatability and good exposure

Very stable white balance (even when mixed with another light source)

Cons:

Fall-off is a bit strong at the corners.

Overall DxOMark Mobile score for Photo: 81

Video Capture

DxOMark engineers put phone cameras through a similarly grueling set of video tests, and you can read their full findings on the DxOMark website here. We'll simply summarize for you. In bright light DxOMark found the Pureview 808 to produce good results with plenty of detail and "pleasant colors." They were less impressed with the lowlight performance when the results where found to be "very noisy" and the autofocus to leave much to be desired.

Pros:

Very good performance in bright light with pleasant colors

Fine details in bright light

Cons:

Very noisy in low light

Autofocus is not very reactive, and cannot reach macro in continuous mode

Stabilization does not correct jello effect, and quality is very scene dependent

Here is the issue I have with this. You don't need 38MP on a mobile phone, zoom or not. As you can see from the images above. You could walk a few meters and stand on the river bed to take the 3.6 x zoom photo. The high resolution has completely taken full focus of the communications when it should be about extending the capabilities of the phone lens, image processing and the great work on the sensor size.

Reading there is a Xenon flash, i figure there is no torchlight on the phone (an LED flash instead of Xenon could be used as a torchlight). That's a pity, i find the torchlight on my phone highly useful. (Or is there a permanent light source on the 808 to be used for video? Then it would be usable as torch.)

I think you should mention the screen resolution and dpi or pixels per cm or something like that in the specs. It is not exactly about photographic quality, but of high interest to photographers anyway. You also discuss resolution in your tablet reviews.

Crap, they removed the Pureview in the Studio Comparison tool in the dpreview site. In summary, there's no compact camera can come close in terms of detail and ISO performance of the 808. So, Canon s100 or Panasonic's LX5 doesn't stand a chance and any phone should be miles away from the 38MP mode.

It's hard to tell since I haven't tried to reduce the image size to match some cameras but it's like a Nikon D800 then blur it by an amount to match it. IMHO though, it's not relevant as long it beats carrying a compact camera. Now, I just want this with a modern operating system.

The problem is.. most "modern" operating systems can't support the 808 tech, they need to be further modernized in order to do so. So in a sense.. the modern ones are still catching up to the old.. outdated one.

I don't see the point in shooting in full resolution mode.. the whole point of the projects was to provide zooming (cropping in real time from the full res image) and also combining pixels, in order to get more detail and less noise.

This new 'camera' is kinda cool having full HD video features. NOT so clear if the stereo minijack serves as Stereo mic input as it should, but no mention so far and no labeling can be seen in the photo galery on the NOKIA site. As always, devices of this complexity would only last a few hours working as a camcorder, but external power remain an option for longer continuous or or extra batteries for non-continuous video recording run times. I usually custom fabricate external battery solutions for many different recording device models when required. While the internal stereo mic is very clean sounding to say the least, it lacks consistant stereo imaging. Very interested to see how this camera/phone works with a special stereo-surround mic I've custom made for personal an industry pro projects. That is, if it works at all with external audio input. See what has been possible with other cameras having external audio input at sonic studios . com / videomic . htm

Did you also take the test chart at full resolution? I can only the 8MP Pureview mode, and that doesn't (quite) capture all the detail that comes from the full resolution shots. At least not in good light.

My #1 criticism is that it doesn't have optical image stabilization. Although, I'd say #2 is the lack of dynamic range.

For the price, I'd have liked the lens cover case thrown in too...

Just, at long last, finally been offered the firmware update. Time will tell whether it can fix the occasional dark images with manual ISO.

I got a new firmware update FP2 last week to my Nokia 808 and it improves and fixes many things on this operating system and now I feel this is a real allover competitor against iPhone 5, Samsung S3 and HTC One X or soon coming new Nokia Lumia, Samsung and HTC WP8 phones. You tested Nokia 808 with its old Nokia Belle FP1 OS - right?

I agree that Nokia 808 blows its competition out of the water at photos and videos because its huge image sensor, oversampling technology and lossless zoom. Besides that 808's quality of the recorded audio is unbeatable - thanks for its HAAC (High Amplitude Audio Capture) microphones (2pcs) the audio is never distorted even at the loudest heavy metal concerts. Its rivals (also iPhone 5) have nonHAAC mics and so the audio is many times distorted. 808's Rich Recording technology can also produce very naturally the low bass sound which these rivals can't do.

Could do with auto-HDR (mentioned in review), panorama (other than the one in the Camera Lover Pack app which isn't very good) and still image stabilisation (also mentioned in review). Other than that, it's brill!